The present invention relates to the field of slings for lifting articles, and the like, with a hoist or crane. More particularly, the sling assembly of the present invention is designed to facilitate the lifgint of oil drums and other articles, onto and off of, an offshore platform, for example.
Heretofore, cable slings (generally used in pairs) with shackles, generally of a type depicted in U.S. Pat. Nos. 1,218,714 or 2,814,521 have been utilized to unload cargo from and to a supply vessel to and from an offshore platform such as one used for the production of hydrocarbon fluids from a subsea well.
These sligns with shackles essentially necessitate that a single workman perform three functions at once: (1) loop and fasten the cable slings around the article or articles to be lifted; (2) hook the lift ring to the hoisting hook on the crane; and, (3) maintain tension on the cable until the hoisint hook takes up the slack and starts lifting the article(s) so that the slings do not slide down the article and create an unbalanced lifting condition. Keeping hold of the slings until lifting has begun can put the workman in jeopardy not only from pinching by the cable slings but, also, from the load itself which can swing unpreditably, particularly if the supply boat is being buffeted by wind and waves. With use, the wire rope which makes up the cable slings has a tendency to fray which can further increase the risk of injury to the workman, both from the possibility of breakage and from coming into contact with the potentially puncturing wire rope.
The sling assembly of the present invention overcomes these difficulties. This sling is comprised of two straps of a high strength fabric cloth, preferably nylon. Each strap is formed into a loop by forming an eyelet in a first end and passing the second end through the eyelet. Each such second end is then attached to a ring by which the sling assembly can be connected to a hoisting hook. A tight-fitting sleeve can be slid along the strap behind the eyelet so that after the sling is placed around an article, it may be maintained in engagement by sliding the sleeve into contact with the eyelet. In this manner, the sling can be placed in gripping engagement with the article to be lifted and the workman can be clear from the area before the hoisting hook takes any load. Further, the high-strength cloth does not form puncture producing loose ends when fraying occurs and, because of its increased flexibility, does not fray as early in it wear life.
Various other features, characteristics and advantages of the present invention will become apparent after a reading of the following description.